DATAMAN S4 MANUAL
Introduction to S4 5
to reload your own custom version of the
library, with your preferred defaults, after
somebody else has used your S4 and
changed the settings.
RESET & BIOS Mode
If RESET is pressed S4 returns to a program
running in the masked ROM of the
microcontroller this is called the BIOS (Basic
Input/Output System). Whilst S4 will run in
this BIOS mode and obey most instructions, it
is not intended to be used without a LIBRARY
loaded into the TPA (Transient Program
Area). The BIOS contains subroutines which
are used to handle input and outputs - RS232,
Keyboard, Display etc. BIOS mode is used
only for development of new library
programs.In BIOS mode, S4 will only
program a 27256 EPROM, of the type used as
a LIBRARY ROM. This section is written for
sake of completeness - it is unlikely that
anyone not developing new software for S4
will want to use the BIOS mode.Whilst the
RESET key is down and the charger attached,
charge is forced into the battery. This gives a
"Jump Start" facility for batteries which are
absolutely flat.S4's microprocessor and RAM
have power on all the time. <$IPower-
up>When
S4 is switched on, it awakens from a SLEEP
MODE and starts operation
at the address pointed to by the Warm Start Vector
(WSV). Loading
and running a library reloads the WSV so that S4
starts operation
in the right place. Pressing RESET points the
WSV back into the BIOS
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